Process of making mixed water gas and coal gas



Dec.13, 1927. 1,652,386

w. D. WILCOX PROCESS OF MAKING MIXED WATER GAS AND COAL GAS riled March20. 1922 2 Sheets-Sheet 1 Dec. 13, 1927.

W; D. WILCOX PROCESS OFMAKING MIXED WATER GAS AND COAL GAS 2Sheets-Sheet 2 Filed March 20. 1922 Panama Dec. "13, 1927.

WILLIAM D. WILCOX, OF IDAHO FALLS, IDAHO.

rnocsss or imxme mrxnn WATER GAS AND con. sis.

Application filed March 20, 1922. Serial No. 545,064.

This invention relates to the complete, or substantially complete,conversion of coal into fixed gases, the hydrocarbon volatiles of the"coal being driven off and converted into gas by heat, while the fixedcarbon residue is converted into water gas by the use of the well knownmethod used in the water gas process.

It is my purpose to provide means for accomplishing this completegasification with the least possible dissipation of heat and with aminimum of manipulation of the gas producing material employed. Whilethe process resembles in some respects that described in my 457,811,filed April 1, 1921, which has matured into Patent No. 1,624,644, thereare difierences in the procedure followed and in the design of theapparatus used which produce differences in the result obtained.

The process and the apparatus used in carrying it out may be morereadily under stood by reference to Figures 1 and 2. Figure 1 is a viewin elevation showing parts in vertical section of the apparatus. Figure2 is a plan view of the apparatus.

The apparatus consists of two gas generators, A, and A,, which may beenclosed in a common casing or constructed inde endently in the usualcylindrical form. Tiiese generators are provided with similar workingparts. a, and a, are charging doors in the top of each generator for theintroduction of gas producing material. 6, and b, are grates.supportingthe bodyof fuel in each generator. 0, and c, are valve controlled inletsfor the admission of air. d, and d, are valve controlled and e,areclinkering doors and 7, indicates an ash removal door and generatorA, has a similar door which isnot shown. Each generator has a valvecontrolled gas outlet, g, on generator A,, and g, on generator A,,

discharging from below the grate into wash' boxes, 72., and h,.

Passages, preferably valve controlled, 5, and 5,, connect each of thegenerator chambers with an intermediate combustion chamber orsuperheater. This chamber is divided by a centrally located partitionwall G into two similar chambers or superheaters, B, and B,. In the'upper part of each superheater are valve controlled waste gas outlets,j, and j,, which, by means of valves, 70, and 7a,, are also made'toserve as inlets for a secondary supply of air. .L is an opening,

copending application No.-

generator.

' valves. The valves is, and I while the valve in passage i, is opened.The

inlets for steam.v e,-

brick placedwithin the combustion chambers. n,'is amanhole used inintroducing the checker brick to chamber B, and a similar manhole whichis not shown is used for chamber B,. o, and 0, are clean out doors forthe removal of dust and ashes which may be deposited in' the lower partof B, and B,. p, and p, are oil sprays which may be added to the plantas desired in order to permitan enrichment of the gas. In be ginning theoperation, one of the generators is partially filled with coke, A, forexample. The other, A,, is filled with the same material nearly to thetop. Combustion is established in eachand continued until the coke hasbecome slightly incandescent. Bituminous coal or similar fuel is thencharged through a, into A, until it is nearly filled. A, is now operatedas a water gas During the blast period air is admitted below the'grateof A, and d, is closed while the escaping gases pass into B, through11,. At this point they are joined by a supply of air entering throu his, and 7', and are fully consumed within t e chamber, imparting theheat generated by the combusion to the checker brick. and wall surfacesand passing out at 7', referably into a waste heat boiler to be used inthe generation of steam. During the steam run or gas making period, theair is shut off b I closing the air are also closed water gas generatedby the admission of steam from d, in A, passes throu h B, and B,,becoming hi hly superheated, t ence into A and down t rough the body offreshly charged coal therein, causing the volatiles of the coal to begiven off as vapors and gases. In passing downward through the .lowerstrata of incandescent coke in A, most of these vapors which would uponcooling condense as liquids are broken u into fixed gases. These gasesmixed wit the water gas from A, pass through the gas outlet pipe, intowash box 75,. en this procedure has been carried on for a time to bedetermined by operative experience the level of the coke in A, will havebeen greatly reduced by oxidation and the fresh coal in A, will havebecome substantially. coked. Operation is now reversed. The fuel in A,is then blasted, the'air blast gases being passed LAMA into thesecondary combustion chambers 13, and B and fully consumed therein toheat the checkerbrick and discharged throu h outlet 7' When the fuel isincandescent, t 1e air is shut off and steam turned on and water gas isnow generated in A, by admitting steam through (l The water gasgenerated is passed through the super-heating chambers B and B, intogenerator A into which a charge of fresh coal has been intro- .duced andout through 9 into wash box h It will be noted that in this procedurethere is no heating through the walls. but all heat a plied is heatgenerated by a combustion oi the fuel itselffbrought into contact withthe material to be heated by a current of gas. Where the severalcombustion chambers or superheaters are enclosed in a common casingproperly lined with material which is relatively non-conducting andwhere the sensible heat of the blastgases is used to make steam, thetotal loss of heat is small and the thermal efliciency of the process ishigh. The volatiles of the coal are at no time submitted to a contactwith oxygen by which they will be completely broken up, but only to sucha degree of heat in the absence of air as is afforded by contact withthe hot coke in the lower level of the generator necessary to crack orbreak them up into non-condensible gases. If care be employed inpurgingthe combustion gases from the generator after the air blast and from thesecondary combustion chambers, B and B the gaseous product will be anadmixture of water gas and richer gases such as form what is commonlyknown as coal gas, with a smaller proportion of inert gases than usuallyresults where coal is coked in ovens and cracks in the oven walls permitthe entrance of flue gases into the interior of the retort to mix and bewithdrawn with the conserved gas.

\Vhile in design of the apparatus and in the process followed much thatis standard in the art has been used, the process as a whole isbelieredto be new and not to have been followed or employed at any timein the past and the results obtained are believed to be superior tothose obtained by existing methods.

I claim:

A process for making mixed water gas and coal gas, which comprises; airblasting a fuel bed in one gas generator to incandescence, passing theblast gases into a superheater, having a baffle wall for conveying thegases downwardly and then upwardly, burning the blast gases therein andthereby heating the superheater, shutting off the air blast and thenadmitting steam to the base of the incandescent fuel, causing theresultant water gas to pass downwardly and then u wardly through thesuperheater and there y superheating the water gas, passing thesuperheated water gas into the upper part of a second gas generatorcontaining a fuel bed having an upper layer of coal, passing the watergas down through the fuel in the second generator, and thereby distillinthe volatiles from the coal, withdrawing t e resultant mixed water asand coal gas from the base of the secontf gas generator, andperiodically reversing the operation of the gas generators.

WILLIAM D. WILCOX.

